The present invention relates broadly to textile machine lubricating apparatus and more particularly to a device for supplying oil to shearing blades attached to a rotating cylinder of a textile material shearing machine.
When processing napped and pile fabrics, the upstanding fabric loops or yarns may be mechanically cut or trimmed from the face of the fabric using a machine to shear off the fabric pile or nap. The amount of shearing varies according to the desired height of the nap or pile and on some fabrics, a very close shearing may be given. Typically, shearing machines use a rotating blade system formed as a large cylinder having two end portions and a series of very sharp curved blades which extend helically between the end portions forming the circumferential periphery of the cylinder. A ledger blade is disposed closely adjacent the periphery of the rotating cylinder and oriented so that the edges of the rotating blades pass over the edge of the ledger blade with an extremely close tolerance to produce a shearing action between the respective blades. A vertically oriented wedge-like cloth rest is provided immediately ahead of the ledger blade, with respect to the rotation of the cylinder. The fabric to be sheared is caused to travel over the cloth rest and as the fabric passes over the tip of the cloth rest, the nap is caused to "stand up" and be presented for shearing. The distance between the tip of the cloth rest and the cylindrical plane defined by the rotating blades determines the amount of shearing because during shearing, the nap projects upwardly from the tip of the cloth rest a predetermined distance into the cylindrical shearing plane. As the blades rotate into the projecting nap, the yarns are forced against the edge of the ledger blade and the portion of the yarns extending beyond the edge of the ledger blade is sheared off.
The shearing blades must remain very sharp to prevent unevenness in shearing a pile or nap. Shear marks can also result from slubs or knots that are caught or nipped by the blades of the shearing device. Shear marks show up badly when light strikes the cloth. This problem is aggravated when the blades become dull from use. Further, due to the relatively high rotational speeds of the shearing blades, heat buildup can cause the blades to become dull due to the frictional contact of the shearing blades with the ledger blade. Accordingly, the shearing blades are commonly lubricated with a suitable oil to slow the dulling process and provide a smooth and effective cut.
As may be suspected, if the shearing blades are supplied with too much oil, it can impregnate and ruin the finished fabric. If too little oil is supplied to the shearing blades, heat can build up and the aforementioned problems occur.
Additionally, shearing machines will typically employ some form of vacuum arrangement to remove cut fibers from the shearing area and this vacuum arrangement can remove oil from the blades as well as any lubricating apparatus accessible by the vacuum.
Accordingly, there exists a need for a shear roller lubricating apparatus which can apply oil to the rotating blades of a shearing machine in a controlled amount and maintain the proper lubrication level while the shearing machine is in operation and further to mitigate the effects of the vacuum arrangement on proper blade lubrication.